Article

Comparison of two dengue NS1 rapid tests for sensitivity, specificity and relationship to viraemia and antibody responses.

Oxford University Clinical Research Unit, Hospital for Tropical Diseases, 190 Ben Ham Tu, District 5, Ho Chi Minh City, Viet Nam.
BMC Infectious Diseases (Impact Factor: 3.03). 01/2010; 10:142. DOI: 10.1186/1471-2334-10-142
Source: PubMed

ABSTRACT Dengue is a major public health problem in tropical and subtropical countries. Rapid and easy diagnosis of dengue can assist patient triage and care-management. The detection of DENV NS1 on rapid lateral flow tests offers a fast route to a presumptive dengue diagnosis but careful evaluations are urgently needed as more and more people use them.
The sensitivity and specificity of the Bio-Rad NS1 Ag Strip and SD Dengue Duo (NS1/IgM/IgG) lateral flow rapid tests were evaluated in a panel of plasma samples from 245 Vietnamese patients with RT-PCR confirmed dengue and 47 with other febrile illnesses.
The NS1 rapid tests had similar diagnostic sensitivities (respectively 61.6% and 62.4%) in confirmed dengue cases but were 100% specific. When IgM/IgG results from the SD Dengue Duo were included in the test interpretation, the sensitivity improved significantly from 62.4% with NS1 alone to 75.5% when NS1 and/or IgM was positive and 83.7% when NS1 and/or IgM and/or IgG was positive. Both NS1 assays were significantly more sensitive for primary than secondary dengue. NS1 positivity was associated with the underlying viraemia as NS1-positive samples had a significantly higher viraemia than NS1-negative samples.
These data suggest that the NS1 test component of these assays are highly specific and have similar levels of sensitivity. The IgM parameter in the SD Duo test improved overall test sensitivity without compromising specificity. The SD Dengue Duo lateral flow rapid test deserves further prospective evaluation in dengue endemic settings.

1 Bookmark
 · 
197 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Viral infections may manifest as acute or chronic arthritis. Joint involvement arises from either direct infection of the joint, through an immunological response directed towards the virus or autoimmunity. Epidemiological clues to the diagnosis include geographic location and exposure to vector-borne, blood-borne or sexually transmitted viruses. Although not always possible, it is important to diagnose the pathogenic virus, usually by serology, nucleic acid tests or rarely, viral culture. In general, viral arthritides are self-limiting and treatment is targeted at symptomatic relief. This article focuses on the causes, clinical features, diagnosis and treatment of viral arthritides.
    Expert Review of Anticancer Therapy 05/2011; 9(5):545-54. · 3.22 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Here, two types of cellulose-based in vitro diagnostic devices are demonstrated for the diagnosis of dengue virus infection in both buffer system and human serum: 1) paper-based ELISA for providing the semiquantitative information of the disease activity of serotype-2 dengue fever to healthcare persons (i.e., monitoring the disease activity with a specific serotype in single patients); 2) lateral flow immunoassays to screen for infection with serotype-2 dengue fever (i.e., rapid YES or NO diagnosis prepared for large populations, in terms of global public health). Paper-based ELISA (specific to serotype-2 dengue fever), which builds off of our previous studies and a revised previous ELISA procedure, owns multiple advantages: 1) high sensitivity (about 40 times higher than the current ELISA-based approaches, due to our therapeutic-based monoclonal antibody) and specificity (specific to dengue virus serotype-2 nonstructural protein-1 antigens); 2) tiny amount of sample and reagent used for single tests; 3) short operating duration (i.e., rapid diagnostic device); and, 4) inexpensiveness (appropriate for use in all developing and underdeveloped nations of the world). Due to the higher sensitivity and shorter operating duration of paper-based ELISA (compared with conventional ELISA, and lateral flow immunoassays also performed in this study), this study has not only been able to perform the diagnosis of dengue virus serotype-2 nonstructural protein-1 antigens in both buffer system and human serum but also to evaluate dengue virus serotype-2 envelope proteins in the buffer system, thus successfully achieving the first such use of these proteins as the target antigen for the development of diagnostic tools. These results provide a more comprehensive understanding for the genesis of dengue fever diagnostic tools (through antibody-antigen recognition).
    Advanced healthcare materials. 07/2013;
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: ABSTRACT Dengue virus (DV) is a mosquito-borne flavivirus and the most prevalent arbovirus affecting the tropical and subtropical regions of the world. In view of the high mortality rate associated with the infection and to reduce the disease burden, it is imperative to diagnose the infection early in the course using a sensitive laboratory assay.In this study, we established and compared in house developed NS1 serotype-specific Reverse Transcriptase PCR (RT-PCR) assay and NS1antigen ELISAs in the differentiation of dengue virus serotypes. 250 clinical samples were tested for presence of NS1 antigen between June2012- June 2013 by NS1Ag rapid and Elisa tests .In house developed NS1 serotype specific RTPCR and CDC Real time PCR was performed on 250 samples based on days of onset of clinical illness. NS1 antigen ELISA showed sensitivity of 92 % and 100% specificity. In house developed NS 1 serotype specific RT-PCR assay , revealed a sensitivity of 95 % and 100% specificity. 100% concordance was observed between NS1 RT-PCR and CDC Real time PCR assay. Most predominant serotypes were Denv-2 and Denv-3. Highest Detection rate was observed in patients who reported from1-7 days post onset of illness.NS1 Ag and RT PCR assay, has the ability to improve the diagnostic algorithm contributing significantly to early diagnosis, clinical treatment and control of dengue.
    IJRSR. 12/2013;

Full-text (2 Sources)

View
28 Downloads
Available from
May 21, 2014